w3cschool_jdango_demo/polls/views.py

from django.shortcuts import render
from django.shortcuts import get_object_or_404
from django.http import HttpResponse, HttpResponseRedirect
from django.http import Http404
from .models import Choice, Question
from django.template import loader
from django.urls import reverse


# Create your views here.

def index(request):
    latest_question_list = Question.objects.order_by('-pub_date')[:5]
    # output = ', '.join([q.question_text for q in latest_question_list])
    # return HttpResponse(output)
    # 模板使用方式1
    # template = loader.get_template('index.html')
    # context = {
    #     'latest_question_list': latest_question_list,
    # }
    # return HttpResponse(template.render(context, request))
    # 模板使用方法2
    context = {
        'latest_question_list': latest_question_list,
    }
    return render(request, 'index.html', context)


def detail(request, question_id):
    # return HttpResponse(f"You're looking at question {question_id}.")
    # 添加404页面展示 方式1
    # try:
    #     question = Question.objects.get(pk=question_id)
    #     context = {'question': question}
    #     print(context)
    # except Question.DoesNotExist:
    #     raise Http404("Question does not exist")
    # return render(request, 'detail.html', context)

    # 添加404页面展示 方式2
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'detail.html', {'question': question})


def result(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'results.html', {'question': question})
    # return HttpResponse(f"You're looking at the result of question {question_id}.")


def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        return render(request, 'detail.html', {'question': question, 'error_message': "You didn't select a choice.", })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:result', args=(question_id,)))
    # return HttpResponse(f"You're voting on question {question_id}")